Gap junctions in cultured astrocytes: Single-channel currents and characterization of channel-forming protein

Neuron ◽  
1991 ◽  
Vol 6 (1) ◽  
pp. 133-143 ◽  
Author(s):  
Christian Giaume ◽  
Catherine Fromaget ◽  
Abdelhakim El Aoumari ◽  
Jocelyne Cordier ◽  
Jacques Glowinski ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Single Channel ◽  
Cultured Astrocytes ◽  
Single Channel Currents ◽  
Channel Currents

Characterization of the ryanodine receptor/channel of invertebrate muscle

1998 ◽  
Vol 274 (2) ◽  
pp. R494-R502 ◽  
Author(s):  
Kerry E. Quinn ◽  
Loriana Castellani ◽  
Karol Ondrias ◽  
Barbara E. Ehrlich
Keyword(s):  
Ryanodine Receptor ◽  
Single Channel ◽  
Microscopic Analysis ◽  
Ruthenium Red ◽  
Electron Microscopic ◽  
Release Channel ◽  
Single Channel Currents ◽  
Channel Currents ◽  
Bell Shaped Curve

Electron-microscopic analysis was used to show that invertebrate muscle has feetlike structures on the sarcoplasmic reticulum (SR) displaying the typical four-subunit appearance of the calcium (Ca2+) release channel/ryanodine receptor (RyR) observed in vertebrate skeletal muscle (K. E. Loesser, L. Castellani, and C. Franzini-Armstrong. J. Muscle Res. Cell Motil. 13: 161–173, 1992). SR vesicles from invertebrate muscle exhibited specific ryanodine binding and single channel currents that were activated by Ca2+, caffeine, and ATP and inhibited by ruthenium red. The single channel conductance of this invertebrate RyR was lower than that of the vertebrate RyR (49 and 102 pS, respectively). Activation of lobster and scallop SR Ca2+ release channel, in response to cytoplasmic Ca2+ (1 nM–10 mM), reflected a bell-shaped curve, as is found with the mammalian RyR. In contrast to a previous report (J.-H. Seok, L. Xu, N. R. Kramarcy, R. Sealock, and G. Meissner. J. Biol. Chem. 267: 15893–15901, 1992), our results show that regulation of the invertebrate and vertebrate RyRs is quite similar and suggest remarkably similar paths in these diverse organisms.

Measurement of single channel currents from cardiac gap junctions

Science ◽  
1986 ◽  
Vol 233 (4767) ◽  
pp. 972-974 ◽  
Author(s):  
R. Veenstra ◽  
R. DeHaan
Keyword(s):  
Gap Junctions ◽  
Single Channel ◽  
Single Channel Currents ◽  
Channel Currents

scholarly journals Characterization of Single Channel Currents from Primary Cilia of Renal Epithelial Cells

2005 ◽  
Vol 280 (41) ◽  
pp. 34718-34722 ◽  
Author(s):  
Malay K. Raychowdhury ◽  
Margaret McLaughlin ◽  
Arnolt J. Ramos ◽  
Nicolás Montalbetti ◽  
Richard Bouley ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Primary Cilia ◽  
Single Channel ◽  
Renal Epithelial Cells ◽  
Single Channel Currents ◽  
Channel Currents

A Calcium-Activated Nonspecific Cation Channel from Olfactory Receptor Neurones of the Silkmoth Antheraea Polyphemus

1991 ◽  
Vol 161 (1) ◽  
pp. 455-468
Author(s):  
F. ZUFALL ◽  
H. HATT ◽  
T. A. KEIL
Keyword(s):  
Olfactory Receptor ◽  
Single Channel ◽  
Membrane Vesicles ◽  
Cation Channel ◽  
Voltage Response ◽  
Antheraea Polyphemus ◽  
Cell Excitability ◽  
Olfactory Receptor Neurones ◽  
Single Channel Currents ◽  
Channel Currents

Single-channel patch-clamp techniques were used to identify and characterize a Ca2+-activated nonspecific cation channel (CAN channel) on insect olfactory receptor neurones (ORNs) from antennae of male Antheraea polyphemus. The CAN channel was found both in acutely isolated ORNs from developing pupae and in membrane vesicles from mature ORNs that presumably originated from inner dendritic segments. Amplitude histograms of the CAN single-channel currents presented well-defined peaks corresponding to at least four channel substates each having a conductance of about 16 pS. Simultaneous gating of the substates was achieved by intracellular Ca2+ with an EC50 value of about 80 nmoll−1. Activity of the CAN channel could be blocked by application of amiloride (IC50 <100nmoll−1). Moreover, in the presence of 1μmoll−1 Ca2+, opening of the CAN channel was totally suppressed by 10 μmoll−1 cyclic GMP, whereas ATP (1 mmol l−1) was without effect. We suggest that the CAN channel plays a specific role in modulation of cell excitability and in shaping the voltage response of ORNs.

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